Assessment of the nutritional value of the menus served in school canteens on the island of Tenerife, Spain

To study the nutritional characteristics of the menus provided in the state primary schools of Tenerife and to assess whether they are adequate for the different age groups of school children. The study is conducted in 52 school canteens, with a population of 8,411 diners aged between 4 and 12 years old. 27 of the 52 school dinner services were managed directly and 25 were contracted out to catering companies. They were selected through a random sampling that was stratified by the different geographic areas of the island. A full menu was taken from each of them: first course, second course and dessert (in some cases, a dairy product, normally a piece of fruit). The food was recorded by weight. For assessing the nutritional input in the directly managed dining rooms, we took information on the menu, how it was prepared, the ingredients used and the proportion of each of these in each dish, the amount of oil and salt added, etc. Hence we calculate the proportion of each ingredient. We then weigh the different rations offered to the school children. In the case of the menus offered by catering companies, the quantity of the ration is weighed in the school dining room and, as the catering company supplies us with the breakdown of all the ingredients used in the dishes, we can determine the composition of the menus. To convert the food into nutrients, we used the Dietsource V 1.0 programme. The school menu is broken down using the diet, dish and food management plan, to give the proportions of active ingredients used, and the Recommended Inputs for the Spanish population are used as a reference for evaluating the nutritional quality of the diet, taking the average of the recommended value for the different age groups for each of the parameters. The carbohydrates account for 54% of the total energy, lipids 27% and proteins 19%. The mean content and standard error for cholesterol is 77.53 +/- 64.30 mg, so the mean cholesterol input per 1,000 kcal is 109 mg/1,000 kcal. Saturated fatty acids contribute 8.6% of the calorie input, monounsaturated fatty acids 11.7% and polyunsaturated fatty acids 9.7%. The fibre input per 1,000 kcal is 11 g. The energy value of the school menu is adequate, the percentage content of proteins is slightly high and the lipid and carbohydrate contents are within the limits. The percentage content of fatty acids is adequate, as are the percentage contents of cholesterol and fibre. The vitamin and mineral contents are appropriate, with the e